A conventional electro-photographic type image forming apparatus includes a plurality of cartridges each including a photosensitive drum.
United States Patent Application Publication No. 2010/239314A1 discloses such image forming apparatus including: a main housing; and a cartridge tray supporting a plurality of cartridges and configured to be pushed in and pulled out of the main housing. The main housing includes a pair of metal plates each being provided with positioning portions, and the cartridge tray is provided with a plurality of pairs of biasing assemblies. Each biasing assembly is configured to bias a corresponding end of a corresponding cartridge in a direction away from the corresponding positioning portion.
According to the disclosed image forming apparatus, the cartridge is subjected to positioning with respect to the main housing upon fixing the cartridge to the positioning portions, and the cartridge tray can be pulled out of the main housing after the cartridge has been spaced away from the positioning portions by the biasing assemblies. Each biasing assembly includes an abutment member configured to abut against the cartridge, and a single support spring configured to bias the abutment member.